Apparatus for discharging compact matter from shaft furnaces



March 24, 1953 Q, M N 2,632,697

- APPARATUS FOR DISCHARGING COMPACT MATTER FROM SHAFT FURNACES Filed Ba 15, 1949 INVENTOR Jazzy/J. 9, ff insw Patented Mar. 24, 1953 APPARATUS .FOR DIS CHARGING COMPACT MATTER FROM SHAFT FURNACES Otto Hubmann, Bad Homburg,"Germany Application December 13, 1 949,'SerialN.0. 132, 77.,4 In Switzerland January 20, 1-949 -5 Claims.

inventi re a es to an app ratus d charging compact matter from shaft-furnaces. Shaft furnaces as, forexample, gas producers iflrgilhfl asification of so id f a frequently fitted with a rotary gr.a te and a water bowl. By meansof {the rotation of the grate the material to be removed, as for example, the residues of ,gasifications, is discharged from the =furnace via a water lock closing the furnace to the atmosphere.

* For shaft ,iurnacespperating with higher pressuresas, vfor example, several atmospheres,- this kind of discharging is unsuitable. In place of a water lock.v discharge, .sluices are used and t whole weight of the charge column rests on a :t'able withta central opening. By means of a :rotarygrate or the :likesituated above this central openingthe residues as, for example, :ashes of a gasified solid fuel, are removed through the central opening toward the discharging sluice. It'fhas been found, however, that, for-example, withthe gasification of solidfuel-by means of oxygen :or oxygen-enriched air and steam under .a. pressure of several atmospheres, the moving parts ofzthis discharging device are easily destroyedor deformed by overheating or corrodingsattacks when coming in contact withthe gasifying means or the incandescent material. 'This may happen even with the use of expensive highly heat-resisting construction materials.

The object of the present invention is to overcome these drawbacks by installing water-cooling in the discharge parts of the gas-producers orsimilar shaft furnaces in which,for example, dioxide of. sulphur is reduced by contact with incandescent fuels in such a way that the movable parts of the rotary grate as well as its bearings,-which are situated in the interior of the furnace, :are cooled by water. The invention can be used with particular advantage with furnaces operating under higher pressures as, for

instance, several atmospheres, or in cases where oxygen and/or steam at higher temperatures come to reaction therein.

The water-cooling, according'to the invention, may, for example, be carried out in such a way that a rotary hood situated above the central opening of the table supporting the charge, is mounted ,onafixed hollow shaft inside ofrthe shaft-furnace. Through the hol- :low shaft the hood is supplied with'coolil -water, which also efiiciently cools the bearings of the hood and allowstheir being arranged .at a .place where the forces acting on the hood can he "borne-without additional moments :of flexure.

According to the invention the hood is provided with awater chamber from whichwater is fed .to all parts of the hood including the particularlyexposed shoes. In spite of the high temperatures prevailing in such a shaft-furnace as, forexample, in a gas-producer or the like, .and the presence of oxygen or other corroding gases it now becomes possible .to attach ananm .lar spur gear directly to the hood, since this gear can also be water-cooledwithout .difficulty. In this .way the discharge .of the waste material as, for instance, the residues of reaction,f is facilitated considerably, since .a central receiving chamber may be provided immediately below the hood, especially if, according to the in- .vention, the hollowshaft, on which the hood is mounted, issupported by two .or more arms ,conmeeting it with theshellof the .gas producer.

In order to avoid the use of packings and stuffing-boxes for the cooling-water inside .of .the gas-producer it is-advantageous. to operate the rotary'hoodasa steam producer which preferably communicates with the vgasification chamber in order to have the same pressure in the water chamber of the hood .as in-thegasification chamber, :thus making it possible for the developed steam .to flow out, for example, into .the shaft-furnace. In this way the apparatus according to the invention-canv be operated with a pressure .of 20 atmospheres or more, without running the risk of additionally stressing the cooling-chambers by pressure differences. The water level in the hood can easily be controlled ..by -arranging outside of the gas-producersr nd communicating with the water chamber .of the hood a water container provided with simple float-valves forkeeping the water at the desired level.

With an apparatus according to the invenitiontheytemperature ofathe -hood remains always below the dewpoint of the gases in the furnace,-so that even with conditions favorable :to-cor-rosion there is {no :dangerof chemicahattacks on the construction-material as, for;;in- :stanceby acids, such as-;sulphur-dioxide;sulphur trioxide or thelikel I Since, according to the inventiom a large- -re- -eeiving chamber is provided ;:bene ath therotary igrate for receivin g..the-waste material to be dishar ed fro t r -mace i becom s :p ssihl ito simp-rove the discharging itself eonsiderably by providing cent-rally below the hollow shaft 10f the hood 'a valve-like discharging device; .forgwthe residues, by means Of which these residues can be transferred from the receiving chamber. to a slulcing chamber of normal design below it. The water-cooled hollow shaft provides a favorable opportunity for installing a hydraulic drive for operating the discharging device for removing the residues or the like, since the water-cooling according to the invention efiiciently protects all the' equipment necessary for this purpose against excessively high temperatures. The invention also makes it possible to considerably decrease the height of the whole furnace plant and thereby bring about a corresponding saving in construction material.

With some shaft furnaces, as, for example, those for the gasification of solid fuels by means of oxygen or oxygen-enriched air and superheated steam or the like under pressure, it is desirable to avoid a cooling-down of the gasifying medium by contact with the water-cooled surfaces of the gas producer and the hood by introducing the gasification means as directly as possible into the fuel-bed. This can be achieved, according to the invention, by leading a fixed feed-line, lined with insulating material, centrally through the fixed hollow shaft and. the hood, so that no bearings or packings are required in connection with the rotary hood.

In some particular cases as, for instance, for the production of gases rich in hydrogen by the gasification of coal with oxygen and steam or the like, it is possible by means of the apparatus according to the invention to feed gasifying medium of several different compositions through the hollow shaft into the fuel-bed as, for example, mixtures of oxygen and steam with varying concentrations of oxygen or even methane-containing gases for the purpose of cracking the methane to carbon-dioxide and hydrogen. In this case several feed lines may appropriately be led through the shell of the gas producer and the hollow shaft, which preferably open into the fuel-bed at different heights. This can be achieved, for instance, by suitably shaping the central top part of the rotary hood and providing it for this purpose with several entrance openings at different heights. The different gasifying medium may be continuously or periodically introduced through these openings. An apparatus according to the invention is shown in Figs. 1 and 2 by way of example. Fig.

1 is a cross-section of the lower part of a gasproducer in which coal is continuously gasified by'means of oxygen and steam superheated to 500 C. under pressure of several atmospheres. At the right hand half of Fig. 1 is shown a crosssection of a discharging-shoe of the hood while at the left hand side is shown a cross-section of the hood body itself. Fig. 2 shows a plan view of the hood with the central cover l2 of the water chamber removed.

-I is the double-walled water-cooled shell of the gas-producer. The column of solid fuels rests on the annular plate 2, the central opening of which is covered by the rotary hood 3. The latter is mounted in bearings on the fixed shaft 4. At thebottom the gas-producer is closed by the conical funnel 5, preferably fitted with an insulating lining 2|. The hollow shaft 4 is connected with this funnel by means of arms 6. The annular spur-gear I is fastened to hood 3 by means of hollow ribs l I and is driven fromthe outside by pinion 8 and shaft 9 in the usual manner. Hood 3 contains the waterchamber H), which communicates through hollow ribs H with the water-chamber l8 of the annular spur gear I. The water-chamber I of the rotary hood which, for example, is filled with water up to the level indicated by the line 22, is protected by the double plate l2 against the column of fuels in such a way that the steam developing in the water-chamber is allowed to escape into the fuel-bed. In case gases of different composition are to be introduced separately through different lines this plate l2 may be substituted by a dome-shaped top-piece with openings at several steps, so that, for example, the different feed-lines led through the hollow shaft may each be connected to a different step, The rotary hood 3 is expediently fitted with discharging shoes l3 for removing the residues of gasification during the rotation of the hood into the interior of the hood and the receiving chamber situated below it. The water-chamber In of the hood 3 communicates, according to the embodiment of the invention shown in Figs. 1 and 2, via the hollow space in the shaft 4 and the arms 6 with the feed-line M, which also con nects the water-chamber II] with a container (not shown) placed at the same height as this chamber and. arranged outside the gas-producer. The water-level of the container can be adjusted in a well-known way by means of a floatcontrolled valve.

It is not absolutely necessary that the hollow shaft 4 be filled with water. The water-cooling of the hood 3 and the hollow arms 6 already effects a sufficient cooling of the bearings. The feeding of the cooling water to the water-chamber ll) of the hood may be done by a special feed-line which expediently can be led through one of the supporting arms of the hollow shaft and the hollow shaft itself. In this case the hollow shaft is extended so far upward that the water cannot run out of the hood and flow into it.

For discharging the gasification residues from the gas-producer a conical valve I5 is fitted below the hollow shaft 4, which periodically establishes a connection between the chamber l9 and the sluicing device of usual design below it. For operating the valve [5 a controlling cylinder I6 is provided, which in the well-known way may be actuated by water, oil or steam under pressure.

Through one of the arms 6 and the hollow shaft 4 the interiorly insulated line I! is led so far upward that it ends just below the plate I2 in order to allow a direct feeding of the gasification means into the fuel-bed.

The apparatus according to the invention also allows the operation of shaft furnaces in cases where highly heated gases are introduced and even when these gases contain heavily corroding constituents or when the shaft furnace has to be operated under pressure of several atmospheres. At the same time a considerable saving of construction material, especially of heatresisting metals, is effected. For the gasification of fuels it becomes possible to operate with fuels rich in ashes and tending toward slag-formation with a relatively low consumption of steam.

What I claim is:

1. In an apparatus for discharging material from a shaft furnace, a stationary furnace charge supporting member provided with a central opening, a perpendicular hollow shaft spaced from the inner edge of said supporting member held in the furnace below said supporting member by at least two hollow supporting arms adapted to to have water introduced therein, ,a covering 5 member above said supporting member mounted for rotation upon a bearing on said perpendicular hollow shaft and extending over the space between said hollow shaft and the stationary supporting member, said covering member comprising a casing containing a water chamber, means for supplying water to said chamber, said covering member also comprising means for urging the lower portion of the furnace charge toward the annular space between the hollow shaft and the inner edge of the stationary supporting member.

2.;An apparatus in accordance with claim 1, comprising means for supplying water to said water chamber through said hollow shaft.

3. An apparatus in accordance with claim 1, in which said covering member is provided with an opening in communication with the interior of said hollow shaft and in which at least one conduit is provided in said hollow shaft for feeding gas to the shaft furnace through said opening in the covering member.

4. An apparatus in accordance with claim 1, comprising in addition means affixed to the covering member for the rotating thereof, and com-- prising also an annular spur gear provided with a water chamber communicating with the water chamber in said covering member.

5. An apparatus in accordance with claim. 1, in which said casing is provided with at least one opening communicating between the water chamber and the interior of the furnace whereby steam formed in said water chamber is directly 7 fed to the furnace charge through said opening.

OTTO HUBMANN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

1. IN A APPARATUS FOR DISCHARGING MATERIAL FROM A SHAFT FURNACE, A STATIONARY FURNACE CHARGE SUPPORTING MEMBER PROVIDED WITH A CENTRAL OPENING, A PERPENDICULAR HOLLOW SHAFT SPACED FROM THE INNER EDGE OF SAID SUPPORTING MEMBER HELD IN THE FURNACE BELOW SAID SUPPORTING MEMBER HELD AT LEAST TWO HOLLOW SUPPORTING ARMS ADAPTED TO TO HAVE WATER INTRODUCED THEREIN, A COVERING MEMBER ABOVE SAID SUPPORTING MEMBER MOUNTED FOR ROTATION UPON A BEARING ON SAID PERPENDICULAR HOLLOW SHAFT AND EXTENDING OVER THE SPACE BETWEEN SAID HOLLOW SHAFT AND THE STATIONARY SUPPORTING MEMBER, SAID COVERING MEMBER COMPRISING A CASING CONTAINING A WATER CHAMBER, MEANS FOR SUPPLYING WATER TO SAID CHAMBER, SAID COVERING MEMBER ALSO COMPRISING MEANS FOR URGING THE LOWER PORTION OF THE FURNACE CHARGE TOWARD THE ANNULAR SPACE BETWEEN THE HOLLOW SHAFT AND THE INNER EDGE OF THE STATIONARY SUPPORTING MEMBER. 